You're always under the microscope, and you don't know which mission you're going to get. It's a surprise.

When I saw the Earth from above, personally, as a spacecraft operator, it certainly reinforced and drove home the fact that there's one place where we can live right now. The seven billion of us are sharing a wonderful planet, and it's an absolute privilege to see it from above.

On the day a country decides not to invest a cent in innovation, discovery or exploration, that country decides to be a tributary to others.

I am definitely a little more nervous for my colleagues when I'm working at mission control than I am myself, on the shuttle.

Definitely you don't become famous by doing something bad that's a professional death sentence.

Nobody is going anywhere in 10 years.

The one thing we can't really train for is weightlessness, real weightlessness. It's a ton of fun. It's pure Newtonian physics. You push in one direction, you go in the opposite direction with an equal force.

My husband and I don't worry about each other the way we might if we didn't have similar jobs. I sometimes get an email where he tells me he's heading off on a mission to do terrain avoidance 50 feet above the ground at 500 knots. And I just say, Okay, have a good flight.

I think it's the entire privilege I had to represent my country. It's not the going to space alone it's to be part of that endeavour and to contribute a very small part to a very important step toward pushing the frontier.

The prerequisite that people have a scientific or engineering degree or a medical degree limits the number of female astronauts. Right now, still, we have about 20 per cent of people who have that prerequisite who are female. So hey, girls: Embrace the very fun career of science and technology. Look at computer science. That's what I did.

I always call myself a space construction worker. We were only the second mission ever to go to the space station. There was nothing on board. We brought the first three tons of equipment, including some of the Imax camera stuff. We literally switched the light on to the station and walked in. It was an assembly mission.

You're less apprehensive when you know what to expect. Also, the first flight is very important in this performance-driven culture I work in it establishes your reputation. If you don't do well, it's probably your last flight.

Most people here don't have a wide emotional range. It's just the type of people astronauts are, they're required to be level.

Definitely you don't become famous by doing something bad that's a professional death sentence. You remember that whatever you do, someone will be watching, and you study all the time. It sounds terrible, but you get used to it. I'm 45, and I'm still at school, essentially.

The opportunities to become an astronaut in Canada were far and few.